Fantasy power ratings of hydroponic and other GU10 lamps.

Having noticed major discrepancies between the advertised power ratings and the real power ratings of some hydroponic GU10 lamps (grow lamps) I decided to test a range of LED GU10 lamps I had. The results are as follows:-
3W RED 1.9W
3W YELLOW 2.8W
3W GREEN 2.6W
3W BLUE 2.9W
3W COLD WHITE 3.2W
3W ULTRAVIOLET 4.1W
4W WARM WHITE 4.1W
3W RGB 1.6 TO 1.8W
3W RGB 1-3W (1W PER LED)
4W WARM WHITE 4.2W (Duracell branded)
2W WARM WHITE 2W (PHILIPS)
6W HYDROPONIC 2W!
6W HYDROPONIC 3W
5W HYDROPONIC 1.9W (6 CHIP)

Most of the three watt lamps are probably based around the BP3102 3W lamp driver chip which explains the variation between the coloured lamps since a standard circuit driving the LEDs at about 350mA will result in a power dissipation dependent on the combined forward voltage of the LEDs. Hence why the red lamp only drew 1.9W.
The hydroponic lamps (grow lamps that use a mixture of red and blue LEDs) are clearly involved in a bogus rating war on ebay as they were between half to a third of the advertised power and are probably just using 3W drivers.
The Philips lamp is the only one that used a capacitive dropper with two different capacitor values in parallel to give a very accurate 2W rating.